Development of a vertical semi-active suspension system using variable hydraulic dampers

Abstract

Plans are being made in Japan to launch luxury cruise trains for sightseeing tours. These trains are expected to use both main and secondary railway lines on the network. Secondary lines in particular can sometimes be subject to significant irregularities because maintenance criteria are lower than for mainlines. As a result, rigid-body-mode vibrations, and in particular those in the 1-2 Hz frequency range, tend to increase, which may result in reduced ride comfort. As such, a secondary suspension damping control system using variable vertical hydraulic dampers was developed to mitigate this type of vibration. The system consists of four dampers, a controller, and four accelerometers. Variable vertical dampers are mounted parallel to the secondary air springs. The damping force can be controlled by the command current. The control algorithm which controls the variable dampers is based on the sky-hook control theory. The controller is also equipped with an algorithm which is geared to monitor the state of the damper, which does not require the use of sensors in the system. The algorithm examines the phase difference between the bounce and pitch vibration modes of the car body with the accelerometers used to control the dampers. When a fault is detected, a fail-safe function is activated, stopping damper controlling automatically. Vehicle running tests using an actual vehicle equipped with the control system were carried out. In the tests, the system reduced the peak in the power spectrum density for vertical vibration acceleration due to the rigid-body-mode vibration of the car body by almost 40 per cent compared to when the system was not used.

Active suspension in railway vehicles: a literature survey

“…Moreover, the lateral acceleration of the bogie is low-pass filtered and half the bogie mass is used as gain to form the force reference for HOD function. The idea of modal control is also applied in the studies by Hammood and Mei [33], Sugahara et al [34], Yusof et al [35], and Qazizadeh et al [36,37].…”

Research on hybrid damping modal semi-active control of high-speed trains

“…Foo and Goodall proposed a control algorithm combining skyhook control and modal control to control the vertical actuator of railway vehicle active suspension system [6]. Sugahara et al applied this control strategy to the vertical semi-active suspension system of railway vehicles, and effectively controlled the bending, bounce, pitch and roll modes of the carbody vibrations [7].…”

Investigation of dynamic motions and vibration reduction methods in railway vehicles

“…Aktif sistemlere göre daha az maliyetli ve basit yapıdadırlar. Çalışmalarda sönümleyiciler genellikle Skyhook yöntemi ile kontrol edilmiştir [22], [23]. Yapısında manyetik alan ile kontrol edilebilen magneto reolojik sıvı içeren Magneto Reolojik (MR) sönümleyiciler çözüm olarak sunulmaktadır [24], [25].…”